Intraseasonal or subseasonal variability refers to climate fluctuations occurring on timescales of approximately 20–70 days. In recent decades substantial progress has been made in understanding its characteristics and dynamics. This progress has helped anticipate its potential benefits or adverse impacts on socioeconomic sectors reliant on climate-sensitive decision-making. Despite progress, intraseasonal variability remains largely unfamiliar outside the climate science community. The Madden-Julian Oscillation, the most prominent intraseasonal variability pattern in the tropics, exerts a remote influence on many regions of the globe, including South America. In this region, intraseasonal variability exhibits distinct characteristics on long (30–90 days) and short (10–30 days) timescales, playing a critical role in modulating wet/dry and warm/cold spells in the La Plata Basin.